This, on a night the Red Sox knew they would be without closer Jonathan Papelbon and setup man Manny Delcarmen because of recent usage. Francona also knew that he would only be able to get a minimum amount of pitches from Daniel Bard and Scott Atchison.
Castro is 3-5 with a 6.65 ERA at Triple-A Pawtucket in 17 appearances, five of which were starts. To make room for Castro, the Sox optioned outfielder Josh Reddick back to Pawtucket. Reddick filled in the last three days in right field for J.D. Drew, who has been out with a right hamstring injury and is expected to return to the lineup Saturday.
"We possibly, potentially, don't have enough innings," Francona said. "So we talked to Red after the game and told him we were optioning him. He flew with us because everything was already packed. He came in and got his stuff today. He's heading back tonight. It was Castro's day to pitch. He may have just got here. He gives us some length because we really don't have a lot of pitching."
Alden Gonzalez is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.